That strikes me mostly like a case of working around quirks in Perl’s OO, like bless with a single argument, rather than an innately useful application, though. Corion and demerphq on the other hand exploit reblessing for lazy realisation schemes, which seems innately valuable.

Now I wonder if that inevitably requires reblessing; do people in languages that preclude changing the class of an object implement lazy realisation, and if so, how?

Makeshifts last the longest.